1. Field of the Invention
This invention relates generally to electrical jacks adaptable for connection into jackfield assemblies and is concerned more particularly with an electrical jack module having integral means for simplifying connection of the module into a jackfield assembly.
2. Discussion of the Prior Art
A jackfield assembly of the prior art may include a rectangular frame defining an opening wherein a linear array of laterally spaced, electrical jack modules extends in cantilever fashion from a longitudinal side of the frame. Each of the modules may comprise a metal tee-bracket having a cross member fastened, as by screws, for example, to the frame and having an orthogonal leg member supporting in vertically stacked relationship a plurality of electrical jack devices of the metal leaf-spring type. Each of the electrical jack devices may include a plurality of vertically stacked contact members, alternate contact members being moveable relative to interposed fixed contact members and having respective cam portions aligned with a plug-receiving aperture in the module-supporting side of the frame. Thus, a cylindrical probe type of electrical jack plug may be inserted axially into any one of the apertures in the module-supporting side of the frame for interference engagement with the aligned cam portions of respective movable contact members to move them relative to the adjacent fixed contact members of the associated electrical jack device.
The contact members of the electrical jack devices in each of the modules may be electrically connected to respective prong-like terminals which protrude from the distal end portion of the module. These prong-like terminals may be electrically connected, as by wire-wrapping, for example, to stripped end portions of respective wires in an umbilical wire harness disposed sinuously in the opening defined by the frame. The wires in the umbilical wire harness may have opposing end portions connected electrically through respective terminals of harness connector devices to respective mating terminals of feed-through connector devices mounted in the other longitudinal side of the frame. Thus, the electrical jack plug, which is inserted into an aperture in the module-supporting longitudinal side of the frame to cause movement of moveable contact members relative to adjacent fixed contact members, may be used to open, close or patch into electrical circuitry connected to respective terminals of the feed-through connector devices mounted in the other longitudinal side of the frame.
However, as the requirements for circuit density have increased, more electrical jack modules have been added to the linear array until they may number as much as forty-eight modules which are laterally spaced from one another in the array. This increase in modules has caused a corresponding increase in the number of prong-like terminals and a similar increase in the number of connecting wires in the umbilical wire harness. Consequently, it has been necessary to increase the number of harness connector devices having respective terminals connected to other end portions of the wires in the wire harness and to increase similarly the number of feed-through connector devices mounted in the other longitudinal side of the frame.
As a result of this increase in modules, each of which includes a metal tee-bracket having a cross member fastened, as by screws, for example, to the frame and an orthogonal leg member supporting a vertically stacked plurality of electrical jack devices of the metal leaf-spring type, the weight of the assembly has been increased considerably. Moreover, the resulting increase of prong-like terminals connected by wire-wrapping to stripped end portions of respective wires in the umbilical wire harness has increased the possibility of errors occurring during the wire-wrapping phase of fabrication and, therefore, has decreased reliability of the assembly process. Also, the additional wires, which are of the solid type for wire-wrapping purposes, and the additional connectors required for the umbilical wire harness have added significant weight to the overall assembly. Consequently, this heavier jackfield assembly may be found cumbersome during removal from equipment and in handling, as during trouble-shooting procedures, for example. Furthermore, the weight of the overall assembly when multiplied by the number of these heavier assembles installed in a piece of equipment have added substantially to the shipment costs of the equipment.